DEBT OBLIGATIONS AND CREDIT FACILITIES - Debt Obligations (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Debt obligations	$ 608,929	$ 615,179
5.03% [Member]
Debt Instrument [Line Items]
Debt obligations	21,429	21,429
6.09% [Member]
Debt Instrument [Line Items]
Debt obligations	50,000	50,000
5.82% [Member]
Debt Instrument [Line Items]
Debt obligations	50,000	50,000
6.75% [Member]
Debt Instrument [Line Items]
Debt obligations	250,000	250,000
2.50% Debt, Term Loan Two [Member]
Debt Instrument [Line Items]
Debt obligations	$ 237,500	$ 243,750